Step One packaging is made from 100% compostable materials. The Step One bag is composed of PLA (Polylactic acid), corn starch and PBAT (Polybutyrate Adipate Terephthalate).

PLA is a bio-based plastic derived from renewable resources, in this and most other cases corn starch. Therefore PLA is often referred to as corn starch plastic.

There are several advantages of PLA:

  • PLA is made from corn starch, which is a renewable resource.
  • PLA doesn't contain toxins.
  • Producing PLA makes less greenhouse gas emissions, compared to standard plastics.
  • The Step One bag is certified compostable according to AS4736.
  • Less energy is needed in order to produce PLA, compared to producing standard plastics.
While our Step One bag is certified biodegradable and compostable according to AS4736, it is not made 100% from renewable materials.

PBAT is petroleum-based and can therefore not be classified as made from renewable sources.

That said PBAT is actually enhancing the composting process and leaves no toxins when composted.

PBAT is known for its flexibility and toughness. This makes it perfect for combination with other biodegradable plastics that have high strength, but are very brittle (like corn starch plastic). This combination is a great way to replace standard plastics with an environmentally safe and biodegradable alternative, that will harmlessly degrade in a short time.

The reason for using PBAT combined with PLA, is that it preserves and enhances the biodegradability of the PLA and adds flexibility and strength similar to standard plastics.

Sources and useful links:





AS4736 Standard:

Sizing Chart
(Size 4/8)
52-57cm 21-22in
(Size 8/12)
62-67cm 24-26in
Small 71-76cm 28-30in
Medium 81-86cm 32-34in
Large 90-95cm 36-38in
Extra Large 100-105cm 40-42in
2XL 109-114cm 43-45in
3XL  119-124cm 47-49in
4XL 128-133cm 50-52in
5XL 137-142cm 54-56in
6XL 146-151cm 57-59in
If you're between sizes, then go up a size ☝️
THICKER Legs? Then go for the BOXER BRIEFS
THIN Legs? Then TRUNKS are for you

Our 30-Day First Pair Guarantee means you can try 1 pair for up to 30 days and if it's the wrong size, then we'll send out a different size, for FREE. Yeah.. Free 💪
Note: If the replacement pair is still not a good fit, we can no longer process a refund or send another replacement pair. I'm sure you'd understand!